Due to the significance of using recycled concrete aggregates in the production of new concrete, considering its low properties compared to natural aggregates, and the positive effect of magnetized water in enhancing the mechanical properties of concrete as discussed in the previous studies, the main objective of this research was to study the influence of using magnetized water on the mechanical properties and durability behavior in terms of freeze-thaw resistance of recycled aggregate concrete. In addition to the effect of different numbers of water rounds in the magnetic field, other variables including steel fibers, super-plasticizers and silica-fume were considered in the concrete production in order to obtain the ideal possible performance for recycled aggregate concrete made with 100% coarse aggregates replacements. For this purpose, a total of 11 concrete mixes were prepared and tested. At the first step, the impacts of the aforementioned variables on the main properties, including workability, water absorption, compressive strength, splitting tensile strength, flexural strength and freeze-thaw durability test were investigated. Additionally, flexural toughness was evaluated in accordance with the post-crack strength (PCS) method and the microstructure of concrete specimens was also detected by using scanning electron microscope (SEM). The majority of the investigations revealed that, while magnetized water is highly efficient in improving the mechanical properties of concrete, it should not be utilized alone to compensate for defects produced by recycled coarse aggregates. The optimum toughness and durability results regarding the fiber reinforced concrete mixes produced with recycled coarse aggregates, were related to samples containing silica-fume and 10-rounds magnetized water. Furthermore, the existence of cement replaced by 10% of silica-fume and 10-rounds magnetized water in the concrete mix MW-SF2, increased the durability of the recycled aggregate concrete by an average of approximately 63%.

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